Effects of ion beam irradiation on morphological and flowering characteristics of chrysanthemum

Chrysanthemum morifolium is an important temperate cut flower for Malaysian floriculture industry and the lack of new local owned varieties led to this mutation breeding research. The objective of this study was to compare the effectiveness of ion beam irradiation in generating mutations on ray florets and nodal explants of Chrysanthemum morifolium cv. ‘Reagan Red’. Ion beams has become an efficient physical mutagen for mutation breeding. The ray florets and nodal explants were irradiated with ion beams at doses 0, 0.5, 1.0, 2.0, 3.0, 5.0, 8.0, 10, 15, 20 and 30 Gy. The 50% of in vitro shoot regeneration (RD50) for ray florets explants was 2.0 Gy and for nodal explants was 4.0 Gy. Thus, relative biological effectiveness (RBE) for ray florets was found 2.0 times higher than the nodal explants. The regenerated plantlets were planted in the greenhouse at MARDI, Cameron Highlands for morphological screening. Overall performance of survival plantlets derived from in vitro nodal and ray floret explants was recorded. The characters studied include plant morphology and flowering characteristic. The ray florets explants were found to be more sensitive to ion beam irradiation and generated more mutations as compared to nodal explants

Identification of Genetic Diversity among Mutant Taro (Colocasia esculenta L. cv WANGI) Using Agro-Morphological Trait and Simple Sequence Repeats (SSR) Molecular Markers

Taro (Colocasia esculenta) is one of the traditional crops with enormous sources of dietary fiber, carbohydrates, vitamins, and minerals contents. Mutation breeding using gamma radiation is one of the most preferred approaches used to induce mutation in taro studies. Molecular markers are widely used to detect such induced mutation and genetic diversity in plants. Therefore, the present study was carried out to evaluate genetic diversity among irradiated taro genotypes in comparison with standard taro variety by using simple sequence repeats (SSR). A total of 200 of M1V4 taro genotypes were used in this study derived from segregating population of chronic-gamma irradiated taro cv Wangi with different ranges of gamma dose. The agro-morphological results revealed that genotype exposure in T6 (120.12 Gy) has the highest plant height (54.53 cm), leaf length (32.24 cm), and leaf width (24.87 cm). Corm's weight was decreased significantly with an increased dose of treatment. All mutants recorded a lower number of corm weight as compared with the control genotype. Out of 10 SSR primers tested, 9 primers have successfully amplified 43 amplicons. The polymorphism information content (PIC) values of SSR markers ranged from 0.20 to 0.80. Cluster analysis classified taro into 3 subgroups mutant and parent genotypes. The results clearly showed that SSR markers are important tools to distinguish mutant genotypes and confirmed their usefulness for phylogenetic studies. Finally, the present investigation indicated that genotypes exposed by T6 (120.12 Gy) are promising high-yielding genotypes that can be recommended as new cultivars and possessed an attractive phenotype appropriate for ornamental use

Studies on the effectiveness of acute gamma and ion beam irradiation in generating flower colour mutation for Chrysanthemum morifolium

Chrysanthemum morifolium is an important temperate cut flower and potted plant for Malaysian local market and exporter. Considering chrysanthemum as a popular vegetatively propagated ornamental plant, induce mutations for breeding purposes are more beneficial. Several of physical mutagens have been used in mutation breeding including x-rays, gamma rays and ion beams. Gamma rays and ion beams are from two different linear energy transfer (LET) which are low and high, respectively. The objective of this study was to compare the effectiveness of acute gamma and ion beam irradiation in generating flower colour mutations on nodal explants of Chrysanthemum morifolium cv. ‘Reagan Red’. The nodal explants were irradiated with acute gamma (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120 Gy) and ion beam (0, 0.5, 1.0, 2.0, 3.0, 5.0, 8.0, 10, 15, 20 and 30 Gy). The optimal dose for in vitro shoot regeneration using acute gamma was in the range of 10 to 15.0Gy and for ion beam was between 3.5 to 4.0Gy. Relative biological effectiveness for ion beam was found 3.75 higher than the acute gamma. The regenerated plantlets were planted in the greenhouse at MARDI, Cameron Highland for morphological screening. The highest frequency of flower colour mutation for acute gamma was 77.8% whilst for ion beam were between 42.3 to 58.3%

A review on gamma greenhouse as a chronic gamma irradiation facility for plant breeding and improvement program

The research on radiation induced mutation has been conducted as one of the promising method of plant breeding in Malaysia since 1980s. Nuclear Malaysia is leading research institute in Malaysia conducting plant mutation breeding research. Gamma Greenhouse facility located in Nuclear Malaysia is one of the irradiation facilities to serve as a chronic irradiation facility for inducing mutation in various organisms including plants, fungi and microbes. Chronic irradiation refers to the exposure of materials at a lower dose rate over a long period of time. Previous studies have shown that this type of irradiation can minimize radiation damages to living materials and produces a wider mutation spectrum, therefore is very useful for trait improvements in irradiated organisms. Experiments on induce mutation using Gamma Greenhouse facility for crop improvement program have been conducted since its first operation in 2009. Various plant species including ornamental and herbal plants, food crops and industrial crops have been irradiated to improve their traits such as higher yield and biomass, pest and disease tolerance, higher bioactive compounds, longer bloom time and many others. Most of these crop improvement programs were done through collaborations with other agencies in Malaysia such as universities, research institutes and government departments. A number of publications on crop improvement using Gamma Greenhouse have been published in local and international journals as well as seminar presentations at national and international levels. The outputs from induced mutation via chronic radiation using Gamma Greenhouse could be of great interest for plant breeders dealing with improvement and development of new cultivars. This paper discusses the activities and achievement in plant breeding and improvement using Gamma Greenhouse Facility in Malaysia

Mutation induction of chrysanthemum (dendranthema grandiflora tzvelev) using gamma and ion beam irradiation

Chrysanthemum is one of the major temperate cut flowers in Malaysia. In chrysanthemum production, there is always a demand for new cultivars with varied flower colours and shapes coupled with other preferred traits. Induced mutation using physical mutagens including gamma ray and ion beam in combination with in vitro propagation can be used to generate variations in ornamental plants. The present study was conducted to generate variations in chrysanthemum to produce new cultivars through nuclear technology in combination with plant biotechnology techniques. In establishing the protocol for in vitro propagation, ray florets were cultured on Murashige and Skoog (MS) medium containing five levels of α–naphthaleneacetic acid (NAA) (0, 0.2, 0.5, 1.0 and 2.0 mg/L) and four levels of 6-benzylaminopurine (BAP) (0, 0.5, 1.0 and 2.0 mg/L). Optimum concentration for callus initiation occurred in medium with 0.5 mg/L NAA + 0.5 mg/L BAP while the concentration for shoot regeneration was optimum in MS medium with 0.5 mg/L NAA + 2.0 mg/L BAP. The highest number of normal shoots was also obtained in medium with 0.5 mg/L NAA and 2.0 mg/L BAP. Medium NAA at 0.5 mg/L + BAP at 0.5 mg/L was established as optimum for callus induction from ray florets explants. Subsequent subcultures were done in medium with 0.5 mg/L NAA and 2.0 mg/L BAP for shoot development. A radiosensitivity (radiation sensitivity) test was carried out to determine the optimum dose for mutation using acute gamma (0 to 120.0 Gy) and ion beam (0 to 30.0 Gy) for two types of explants (ray florets and nodal explants) based on their in vitro survival and shoot regeneration. The results showed that the optimum dose for mutation induction of ray florets explants using acute gamma was less than 41.36 Gy and the corresponding dose for ion beam was less than 10.48 Gy. The shoulder dose for irradiated ray florets explants using acute gamma and ion beam were approximately 10.0 and 2.0 Gy,respectively. The optimum dose for mutation induction of nodal explants using acute gamma and ion beam was less than 43.33 and 10.32 Gy,respectively. The shoulder dose for irradiated nodal explants using acute gamma and ion beam were approximately 10.0 and 3.0 Gy, respectively. The result suggests that the relative biological effectiveness (RBE) for ray florets and nodal explants was 3.95 and 4.20, respectively. The in vitro propagated plantlets were grown in Cameron Highlands,Malaysia (elevation: 1500 m) to evaluate the changes on morphological and flowering characteristics of plants. 16 categories of plants were established in the field: Those derived from ray florets – acute gamma treatment (10.0 and 20.0 Gy) and ion beam treatment (0.5, 1.0 and 2.0 Gy); plants derived nodal explants - acute gamma treatment (10.0, 20.0, 30.0, 40.0 and 60.0 Gy) and ion beam treatment (0.5, 1.0, 2.0, 3.0, 5.0 and 8.0 Gy). Results showed that the ion beam totally altered the plant morphology and flowering characteristics (except the response time) of plants derived from ray florets explants. Acute gamma only altered the flowering characteristics (except the response time). Leaf characteristics were altered by both mutagens. Both acute gamma and ion beam did not alter the morphology of plants derived from nodal explants but showed marked differences in the flowering characteristics especially on the number of buds and flower colours. Both mutagens altered the leaf characteristics such as leaf colour, blade length and shape. In conclusion, ray florets explants are more sensitive to both types of physical mutagens as compared to nodal explants. Ion beam was found to be more effective than acute gamma in inducing mutations for Dendranthema grandiflora cv. ‘Reagan Red’

Generating new ornamental plant varieties using ion beams

Chrysanthemum is one of the most important ornamentals for both local and international market. One of the main problems for chrysanthemum in Malaysia is the lack of new varieties to meet the ever-changing customer demands. For this purpose, mutagenesis of chrysanthemum was carried out using a combination of ion-beam irradiation and in vitro organ cultures to produce new cultivars with novel traits and wider mutation spectrum. Ray floret and nodal cultures of chrysanthemum were irradiated at various doses with 320 MeV 12C6+ ion beams. Eight mutants were selected based on their uniqueness and/or suitability for cut flower production. Among them, TIARA Red, Golden Eye, and Yellow Sun generated from Regan Red variety, and Majestic Pink from Pink variety have been filed for Plant Variety Protection (PVP) with Department of Agriculture (DOA) Malaysia

Mutation Breeding of Rice for Sustainable Agriculture in Malaysia

アジア原子力協力フォーラム(FNCA)放射線育種プロジェクトで、主に2013年度から2017年度にかけて実施されたサブプロジェクト「持続可能な農業のためのイネの突然変異育種」に関してマレーシアで実施された研究成果を取りまとめた報告書である。乾燥に強く多収のイネ品種NMR152の開発と普及、及びイオンビームを利用した新奇変異体の選抜等について記載